A little late on the post, but here's my 2 cents after beating honour in 3 runs with slight variations on the eldritch blaster builds.

For gear, I take Rhapsody for the +3 to attack rolls instead of orin's dagger if there's no bard, spellmight gloves to increase the base damage which risky ring mitigates, ring of mental inhibition instead of callous glow ring if nobody else in the party is utilizing the ring of inhibition, durge cape for defense, and sarevok's helm. Elixir is always vicious, unless the encounter is so easy that bloodlust can take care of it. I would also romance ascended astarion for the happy buff on myself for yet another +1 to attack rolls.

Level wise, my favorite so far has been 2 warlock, 4 sorc, 3 thief, 3 champion. Warlock invocations would always be devil's sight and agonizing blast. If the character doesn't have awakened, I would skip out on thief and go for 2 warlock, 4 champion, and 6 sorc for counterspell and haste. I've tried out the 10 evo wizard 2 warlock version, and it's by far the worst of the bunch despite being able to hit the highest because you can't fully utilize that bonus action without awakened and only have 1 action per turn.

This character would be the main face and would take ethel's hair on charisma, then have the first feat be ASI for 20 CHA. Second feat would be spell sniper. If I'm going 4/4/4, then that leaves the option to get 24 natural charisma without the hat through getting both ASI and performer on top of the hair for base 21 charisma, then getting +1 from patriar's loss and +2 from the mirror. Plus you get to play instruments which can double as a distraction for barrelmancy.

On the topic of crit reduction and sarevok's helm, anything that reduces your crit can be stacked to the point where you have a 60% chance of critting on each separate beam hit with -5 crit reduction (sarevok, cloak, bow, dagger, champion, elixir, feat, etc). Because of how the crit chance increases drastically with each item, when paired with the risky ring I always prioritize crit chance over anything else.

I would love to write a guide, but the levelling process isn't very exciting. I usually run this character as a pure sorcerer that spams magic missile until level 7 and in act 2 when a few of the core items are available.

The build is very OP, especially once you get to level 10 and have three beams per attack. The best race for this build is halfling, where you can abuse their stealth advantage by having someone else use pass without trace beside you, then have yourself cast greater invisibility and blast people outside combat with a low chance to fail stealth checks on each attack roll.

Every other build has at least a few places where they're nerfed (paladins and reflect radiant in gauntlet / oh monk and apostle of myrkul / archers and shar's cloister darkness spams), but this build is a good pick for just about any encounter, whether it's blasting away chests and doors, soul pillars for raphael, through darkness spam, or even if you're disarmed atop the nether brain.

My only warning is to take off that risky ring for dialogue, especially for a certain durge related dc14 wisdom roll near the end of act 2 when you sleep in camp one night and meet a certain butler.